The present invention relates to a fluid-sealed vibration insulator which is applicable to a suspension and an engine mount for automotive vehicles, and relates to a method for producing such a fluid-sealed vibration insulator.
Various liquid-sealed vibration insulators have been proposed and in practical use. A Japanese Patent Provisional Publication No. 6-50135 discloses a typical liquid-sealed vibration insulator which has a pair of liquid chambers connected with each other through an orifice passage. This conventional vibration insulator is arranged to generate a damping force by flowing liquid between the liquid chambers through the orifice passage according to a volumetric change of the liquid chamber caused by vibration input thereto.
However, such a conventional liquid-sealed vibration insulator is constituted by several elastic members and several rigid members. Accordingly, it is necessary to prepare several forming dies for elastic members. This generally increases steps for producing vibration insulators and the production cost thereof.
It is therefore an object of the present invention to provide an improved liquid-sealed vibration insulator and a method for producing the same. This liquid-sealed vibration insulator has a simple structure which largely improves production steps as compared with the conventional one while one while satisfying a vibration damping performance.
An aspect of the present invention resides in a liquid-sealed vibration insulator which comprises an inner cylinder, a first ring having a L-shaped cross section, a second ring, an orifice ring, an elastic member and an outer cylinder. The orifice ring has a U-shaped cross section. The orifice ring is located between the first and second rings. The elastic member of a cylindrical shape has a cylinder inner surface to which the inner cylinder is integrally connected, and a cylinder outer surface to which the first ring, the orifice ring and the second ring are integrally connected. The elastic member has a first groove formed on the cylinder outer surface between the first ring and the orifice ring and a second groove formed on the cylinder outer surface between the orifice ring and the second ring. The outer cylinder is integrally connected to the first ring and the second ring. The outer cylinder and the first groove define a first liquid chamber. The outer cylinder and the second ring define a second liquid chamber. The outer cylinder and said orifice ring define an orifice passage fluidly communicating the first and second liquid chamber. The first and second liquid chambers and the orifice passage are filled with liquid.
Another aspect of the present invention resides in a method for producing a liquid-sealed vibration insulator. The method comprises a step for molding an elastic member of a cylindrical shape, a step for forming a plurality of projections on an inner surface of an outer cylinder and a step for assembling the elastic member and the outer cylinder in liquid. The molded elastic member has a cylinder inner surface integrally connected to an inner cylinder and a cylinder outer surface integrally connected to a first ring, an orifice ring and a second ring. The elastic member has a first groove formed on the cylinder outer surface between the first ring and the orifice ring and a second groove formed on the cylinder outer surface between the orifice ring and the second ring.